A hybrid broadcast service based on cooperation with an Internet protocol network corresponds to a representative application to be utilized in future Digital Television (DTV) services. The hybrid broadcast service refers to a service for transmitting enhancement data associated with broadcast Audio/Video (A/V) content transmitted over a terrestrial broadcast network, or a part of the broadcast A/V content over an Internet protocol network in real time. As such, users may experience various types of content.
A network structure for supporting the hybrid broadcast service is expressed using protocol layers. A group of various protocol layers is called a protocol stack. In general, the protocol stack includes an application layer, a transport layer, a network layer, a link layer, and/or a physical layer. A transmitter end sends data downwards from the application layer corresponding to the top layer of the protocol stack. Whenever the data passes through each layer, additional information to be used by the layer is added to a header of a packet. In contrast, a receiver end sends data upward from the physical layer corresponding to the bottom layer of the protocol stack.
Meanwhile, a legacy broadcast system includes and transmits signaling data in a broadcast signal to allow a user to rapidly receive a broadcast service or a broadcast component. The signaling data not only includes information about each stream of a transmitted broadcast service but also includes additional information, e.g., the name of the broadcast service.
Unlike a legacy broadcast system for transmitting a broadcast signal over a single broadcast network, a hybrid broadcast system is capable of providing various broadcast services and components to users. However, as various broadcast services are provided, the size of data to be transmitted is increased and thus a time taken to receive the broadcast services is also increased. In addition, since a user can change broadcast channels more frequently, a time taken by a receiver to find a selected broadcast channel is increased.